These plots are rather difficult to interpret simply.
But rather vaguely, the top plot shows of frequency of hot and cold spots of various angular sizes on the sky (FK-652--653). Large spots are on the left; small spots on the right.
The data points come from the WMAP satellite and other detectors.
The curve is fit to the data???---but with how many free parameters---of what is called a scale-invariant power spectrum which is a prediction of most inflation models irregardless of the details of the inflation mechanism (CL-263,265,274--275; Gr-309).
The fact that inflation predicted the observations is an astonishing triumph of the inflation idea.
It does NOT prove inflation, but it certainly strongly supports it.
Credit/Permission: NASA/WMAP Science Team / Public domain. Download site: NASA/WMAP Science Team: Images: Other Images, but this particular image no longer seems be posted. Image link: Itself.